Melt 2 tablespoons of butter (or oil) in a saucepan over LOW heat.
Add 2 tablespoons of flour, and whisk to combine.
Bring up to a simmer, and allow mixture to continue to barely simmer for 2 to 5 minutes. This will cook out the flour taste, but you don’t want it to boil and evaporate all of the liquid.
Pour in the beef stock, whisk to combine and bring just to a boil. Reduce heat and simmer stirring occasionally until gravy thickens.
Season with sea salt and ground black pepper to taste and pour into a gravy boat or bowl with a ladle for serving.
Notes
The longer you cook the roux, the darker it will become.
For thinner gravy, use 1 tablespoon of butter and 1 tablespoon of flour.
For even more flavor, add chopped rosemary, thyme, or sage at the end of cooking.
To use cornstarch: mix 1.5 teaspoons of cornstarch with 1 tablespoon of water to create a slurry. Pour into the hot beef stock and whisk to combine.